Secure backups let you save an archive of your Signal conversations in a privacy-preserving form
Recently, my Dad upgraded his iPhone and needed to move all of his apps from one phone to another. As anyone has done this will know, messages from encrypted messaging services such as WhatsApp and Signal usually have to be backed-up and then restored separately to the rest of the app transfer.
WhatsApp makes this easy, but much less secure, by allowing users to back up to Google Drive or iCloud. This is, by default, not encrypted, so it’s an easy vector for hackers and state-level actors to target. Signal, on the other hand, requires either device-to-device transfer of messages, or manual backup and restore.
Signal has just announced secure backups, which is a major step forward. After all, while you could regularly auto-backup Signal chats to local storage, if you lost or broke your phone, those messages were irretrievably lost.
After careful design and development, we are now starting to roll out secure backups, an opt-in feature. This first phase is available in the latest beta release for Android. This will let us further test this feature in a limited setting, before it rolls out to iOS and Desktop in the near future.
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Secure backups let you save an archive of your Signal conversations in a privacy-preserving form, refreshed every day; giving you the ability to restore your chats even if you lose access to your phone. Signal’s secure backups are opt-in and, of course, end-to-end encrypted. So if you don’t want to create a secure backup archive of your Signal messages and media, you never have to use the feature.
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This is the first time we’ve offered a paid feature. The reason we’re doing this is simple: media requires a lot of storage, and storing and transferring large amounts of data is expensive. As a nonprofit that refuses to collect or sell your data, Signal needs to cover those costs differently than other tech organizations that offer similar products but support themselves by selling ads and monetizing data.>
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Once you’ve enabled secure backups, your device will automatically create a fresh secure backup archive every day, replacing the previous day’s archive. Only you can decrypt your backup archive, which will allow you to restore your message database (excluding view-once messages and messages scheduled to disappear within the next 24 hours). Because your secure backup archive is refreshed daily, anything you deleted in the past 24 hours, or any messages set to disappear are removed from the latest daily secure backup archive, as you intended.
Source & image: Signal blog